Method of providing a head space within a filled container



p 1967 E. R. ANDERSON 3,342,009

METHOD OF PROVIDING A HEAD SPACE WITHIN A FILLED CONTAINER Filed June 11, 1962 INVENTOR. EA/PL R. ANDERSON A T TOP/V575 United States Patent 3,342,009 METHOD OF PROVIDING A HEAD SPACE WITHIN A FILLED CONTAINER Earl R. Anderson, Campbell, Calif, assignor to Philip H. Allen, Saratoga, Calif. Filed June 11, 1962, Ser. No. 201,711 4 Claims. (Cl. 53--22) The present invention relates to filled containers of food and the like, such as cans, wherein it is desirable to have a certain degree of vacuum within the container after the container is filled, closed, sterilized and cooled or filled and closed and to provide a head space within the container above the contents thereof, and is concerned more particularly with means and method for causing a vacuum condition within the container by causing flexing of the end wall thereof to an outwardly bowed or dished condition as opposed to the normally inwardly bowed or dished condition of such walls and to maintain said wall in outwardly bowed condition by including reinforcing means in connection with the end wall to hold it in the desired position.

It is a general object of the invention to provide an improved can for products such as food stuffs, for example, wherein the container is provided with a vacuum condition within the container and one of the end closures of the container is bowed or dished outwardly.

Another object of the invention is to provide in the canning of food stuffs an improved method for obtaining a vacuum condition within a container and to provide a head space within the container.

Other objects and advantages of the invention will be apparent from the following description of a preferred embodiment thereof made with reference to the attached drawings, in which:

FIG. 1 is a sectional elevational view of a container embodying the invention and one form of apparatus for controlling the position of an end wall of the container;

FIG. 2 is a sectional elevation similar to FIG. 1 but showing the end wall of the container in an outwardly bowed condition;

FIG. 3 is a perspective view of one element of the end closure;

FIG. 4 is a perspective view of the other element of the end closure.

Referring first to FIG. 1, the container or can as illustrated is made up of a peripheral side wall 11 which in this case is cylindrical, a first end closure 12, and a second end closure 13. The container is seated in a stop fixture such as a vacuum cup 16 having a rubber seal ring 17 therein to engage tightly around the adjacent end closure, and having a central orifice 18 which leads through piping 19 to a suitable source of vacuum pressure.

The end closures 12 and 13 are connected in a conventional manner by rolled overlapping seams 21 to the peripheral sidewall 11. The second end closure 13 is two part in construction including a first part 14, which is flexible in the usual fashion of the end wall of a can and under vacuum pressure will move to a bowed condition as illustrated in FIG. 1, being similar in this respect to the end wall or closure 12. The second part 22 of the closure 13 comprises a permanently bowed metallic disc which is of a size to fit snugly within the upright wall portion 23 of the closure portion 14 and which at its center has an aperture 24 of a size to fit over a cylindrical upright tube or projection 26 which is attached centrally of the part 14 as by soldering.

The outer part 22 as seen in FIG. 2 is formed with an outwardly bowed or dished shape and is apertured to receive the projecting tubular portion 26 of the inner or first part 14 within its aperture 24 and the edges of the tube 26 can be rolled or peened over as indicated at 26a in FIG. 2. At this time, the closure part 22 and the closure part 14 are in tight flush engagement with each other and may be secured to each other as by soldering at the inner or outer edges for example or with light spot welds.

The process will be described first as employed with a canned product acquiring a cold fill processing. As illustrated in FIG. 2, the vacuum pressure through the piping 19 is used to draw the end closure 14 from its inwardly dished or bowed condition which it occupies when cold to an outwardly dished or bowed condition to thereby produce a head space Within the can and to produce a vacuum therein. During the movement of th closure part 14 outwardly from the position shown in FIG. 2, the tubular projection 26 will engage the frustoconical surface 27 of the stop fixture 16 and will be rolled over by this frusto-conical surface 27 to the condition shown in FIG. 2 to provide the flange 26a overlapping with respect to the closure part 22. After removal of the can from the fixture, soldering can be performed at the inner and outer edges of the closure parts 14 and 22 if desired.

When the product is such that in canning it is necessary to subject it to usual filling, exhausting, closing, cooking and then cooling process, the reinforcing of the end wall 13 of the container can be effected immediately after the cooking process when both end closures 12 and 13 will be dished or bowed outwardly due to the pressure condition in the can. This condition of the end closure 12 is indicated in dotted lines at 12a in FIG. 2. While the can 11 is still hot and the closure part 14 is dished outwardly, as seen in FIG. 2, either a frusto-conical forming part 27 can be used to roll the edge 2611 over, or it can be formed in other ways. Also a soldering operation may be performed while the can is in this condition.

Subsequently, upon cooling, the end closure or wall 12 will be dished inwardly as seen in FIG. 2 so that the conventional test for the spoiled and unspoiled conditions within the can may be made by flipping vacuum of the end wall 12.

In the canning of certain products such as golf balls, tennis balls, cigarettes and the like, where the product is canned cold and there is no requirement for heating in the canning process, the cold product is placed in the can and the can is sealed with or without vacuum. According to my method, the can is heated to expand one end to an outwardly bowed condition. In certain instances, for example, when a vacuum pack is employed, the opposite end may be held or retained in a straight or inwardly bowed condition during this heating step. The permanently bowed closure 22 is applied and is fastened at the inner and outer edges by soldering as previously described. It will be noted that where the can was sealed without a vacuum condition in it, the expanding of one end to a bowed condition and holding this end in the bowed condition produces a vacuum in the can. Where a vacuum condition already exists, the amount of vacuum is increased.

While I have shown and described certain preferred forms and methods of this invention, it will be apparent that the invention is capable of variation and modification from the forms shown so that its scope should be limited only by the scope of the claims appended hereto.

What I claim is:

1. A method of providing a head space within a filled can having a side wall and two end closures connected thereto, which comprises filling the can, closing the can, then moving at least one of said closures to an outwardly dished condition, and reinforcing said one closure while in said outwardly dished condition to retain said dished condition.

2. A method of providing a head space Within a filled can having a side wall and two end closures connected thereto, which comprises filling the can, exhausting the filled can, closing the can, heating the can to move said closures to an outwardly dished condition, and reinforcing at least one of said closures while in said outwardly dished condition to retain said dished condition.

3. A method of providing a vacuum Within a sealed can having a side wall and two end closures connected thereto, which comprises filling the can, closing the can, heating the can to move at least one of said closures to an outwardly dished condition, and reinforcing the outwardly dished closure while in said outwardly dished condition to retain said dished condition.

4-. A method as recited in claim 3 in which the other end of said closures is held against outward displace- 4 ment while said one closure is moved to an outwardly dished condition.

References Cited UNITED STATES PATENTS 547,225 10/ 1895 McLaughlin 2-20-68 1,341,638 6/1920 Gogay 22068 1,611,133 12/1926 Mauran 22068 1,819,437 8/1931 ONeil et al 539 2,329,311 9/1943 Waters i 53-37 X 2,349,588 5/ 1944 Brand 539 2,942,390 6/ 1960 Lerner 53-22 2,971,671 2/1961 Shakman. 3,103,089 10 /1963 Allen 53-37 15 TRAVIS S. MCGEHEE, Primary Examiner. 

2. A METHOD OF PROVIDING A HEAD SPACE WITHIN A FILLED CAN HAVING A SIDE WALL AND TWO END CLOSURES CONNECTED THERETO, WHICH COMPRISES FILLING THE CAN, EXHAUSTING THE FILLED CAN, CLOSING THE CAN, HEATING THE CAN TO MOVE SAID CLOSURES TO AN OUTWARDLY DISHED CONDITION, AND REINFORCING AT LEAST ONE OF SAID CLOSURES WHILE IN SAID OUTWARDLY DISHED CONDITION TO RETAIN SAID DISHED CONDITION. 